Method and apparatus for preparing combustible mixtures



Nov, 15, 1927.

v 1,649,278 F. E. ASELTINE METHOD AND APPARATUS FOR PREPARING COMBUSTIBLE MIXTURES Filed Aug. 2. 1920 2 Sheets-Sheet 1 35 i? /2 T" 43 ///r 2 4247 /2 \Q l 3 V f I r /4 F 15/5; 4? 50 43 lg s 3 A 4@ 45 49 ,5 i 4 415 l ,1

| 2/ 5 3? 5 l a 1 5.5 573.5 2 v 30 24853 gj i O Nov. 15, 1927. 1,649,278

F. E. ASELTINE METHOD AND APPARATUS FOR PREPARING COMBUSTIBLE MIXTURES Filed Aug. 2. 1920 2 Sheets-Sheet 2 514.0: 44 to c Patented Nov. 15,1927.

UNITED STATES PATENT OFFICE.

FRED E. ASELTINE, OF DETROIT, MICHIGAN, ASSIGNOR TO GENERAL MOTORS COR- PORATION, OF DETROIT, MICHIGAN, A CORPORATION OF DELAWARE.

' mn'rnon AND arrnnn'rus ron rnnranme comnusrrnnnmxrunns.

Application filed August 2, 1920. Serial No. 400,745.

The invention relates to the formation of combustible mixtures, more particularly for use in internal combustion engines, and has for its primary object the provision of a method and apparatus for delivering to an internal combustion engine a homogeneous explosive charge in which the liquid fuel shall be thoroughly commingled with the air notwithstanding low volatility of the fuel employed. In devising means for carrying out this object I have provided for the formation first of a rich mixture ofprimary air and fuel one at least of which maybe heated, then the subjection ofthis mixture to a treatment whereby the less fully vaporized or nebulized port-ion of the fuel may be separated from the more completely nebulous portion than thesubjection of the portions to suitable heat treatment followed by reuniting the separately treated portions and supplying them to the point of use with the further admixture of an additional quantity of air.

The invention comprises the method of .and apparatus for carrying out the steps above set forth, together with various subcombinations and details thereof 7 as more fully described hereinafter and set forth in the appended claims.

In the accompanying drawings, Fig. 1 1s a side elevation with parts in section of an internal combustion engine with one embodiment of my invention shown in assembled relationship thereto.

Fig. 2 is an end View, partly 1n sect on, of thestructure'shown in Eig .1.

Fig. 3 is a section on line 3--3 of Fig. 1. Fig. 4 is a section on line 4 4 of Fig. 1. 'Fi 5 is a view similar to Fig. 1 but 4 showlng a modified form of structure.

Fig. 6 is a view showing the charge-'form ing mechanism only of Fig. 5, but on an enlarged scale and partly in section.

Referring to the form illustrated in Flgs. '45 1 to 4, inclusive, IOindicates an lnternal combustion engine which is shown as a surcylinder engine of conventional type, having intake apertures at 11 and exhaust outlets at 12. The gxhaust outlets open into an exhaust 1nanifold 13 divided into twobr'anches 14, 15 by a partition 16. An opening 17 formed in the partition adjacent; one end and an opening 18 adjacent the other end provide for by-passing a portion of the exhaust gases 55 through theibranoh 15, the proportion of gases passingtherethrough being determinable by the ad ustment of a valve 19 near the end of branch 14.

A carbureter 20 adapted preferabl to form a IlCll mixture of liquid fuel an air but w1th the particular construction of WhlCh my invention is not directly concerned, may be supplied with fuel from a tank 21 of usual character, through a pipe 22. An air conduit 23 which may be provlded with a choker valve 24 is arranged to supply primary air to the carbureter and a prlmary throttle valve 25 is mounted at the upper end of the carbureter mixing chamber. A choker'rod 26 may extend to the dash or other convenient point for operation of valve 24 when desired, as in starting when the engine is cold. The primary air at least is preferably heated and I have shown for that purpose a conduit 27 connected to a heatlng pipe 28 arranged adjacent the exhaust manifold 13 and preferably cast as a part thereof.

Above the throttle 25 is a separator 30 comprising an enlargement in the intake passage shown in cross-section in Fig. 3. This enlargement is formed with a main passage 31 and an auxiliarypassage 32, the passage 32 being situated to one side of the passage 31 and communicating with the .latter through a slot 33 approximately tangen tial to the perimeter of the main passage.

trally positioned in the main passage, is provided with a series of conical enlar ements 35 carrying on the lower faces bla es or fins 36 arranged at an angle to the axis of the tube so as to cause a whlrling movement of the mixture passing through the conduit 31. The arrangement is such that the centrifugal effect tends to-carry the heavier portions such as the less fully nebuli zed globules or articles of fuel out through the slot 33 an into the auxiliary passage 32. Holes 37 are provided in the tube 34 through which more fully nebuliz'ed mixture may pass to the interior of the tube.

The upper end of the tube 34 communi-v cates with a heating chamber 40 in which provision is 'made for applying any heat treatment desired. As shown in this form an electric heater 41 of any usual charpcter is arranged in the chamber 40 and may be supplied with current through the conductor 42, control devices for which'may be posi- A tube" 34 with its lower end closed, centioned at the dash or may be made automatic if desired. The heating chamber 40 discharges into a primary mixture manifold 43, branches of which lead to each of the intake openings 11. a

The auxiliary passage or chamber 32 of the separator opens into a pipe 44 which leads to a heating chamber formed by a conduit 45 with a horizontal partition 46 therein and located in the branch 15 of the exhaust conduit, the partition being interrupted near the end at the left in Fig. 1. The pipe 44 leads to the heating chamber 45 below the partition (see Fig. 4) and an outlet pipe 47 leads from the chamber above the partition, the result being that any mixture' flowing through the pipe 44 is caused to pass through the heating chamber a distance equal to substantially twice the length of the chamber.

The dischare end of pipe 47 is downwardly direct as at 48 and arranged within a trap chamber 49 from the'upper end of which a tube 50 leads to the primary intake manifold 43. In the lower part of trap chamber 49 is an over-flow or stand pipe 51 the outlet of which is controlled by a valve 52 arranged to close under the influence of engine suction. The trap chamber discharges into a pipe 53 which is shown as con-- Znecting with the fuel line 54 leading to the main fuel tank. Other arrangements of devices for utilization of the separated fuel may be provided, for example a pipe '53 controllable by suitable valves as desired may lead to the carbureter so that the separated fuel may be recirculated until it has been entire'ly converted to suitable condition for utilization in the engine.

The mixtures of fuel and air coming from heating chamber 40 and from trap chamber 49 commingle in the primary mixture manifold 43 and flow to the engine intakes 11..

At that point, or as near as possible to the point of entry to the engine cylinders, secondary air is added to the rich mixture to form the desired explosive'gas. This secondary air is supplied through the inlet 55 controlled by the secondary throttle 56, which latter may be connected with both the primary throttle 25 as by the adjustable conmotion 57, and with the valve 19, as by the rod 58. An additional automatic air valve thg atmospheric pressure operatin upon the lower sur ace of the plate ten s to lift it and the sleeve 59, thereby causing the plate 60' to swing toward an open position by reason of the connection of one edge to a fixed point through the rod 60'. The opening through the control sleeve is therefore varied in accordance with the suction operating in the air intake. The details Oftl'llS construction are not claimed in this application, being covered in a co-pending application. The secondary air is conveyed to the point of admixture with the rich mixture through 'the air intake manifold 61. The air intake manifold and primary mixture manifold 43 may be arranged adjacent to each other and may be integral, as shown, the heating effect of the exhaust manifold being communicated to the latter to some extent thereby maintaining the primary mixture in homogeneous condition until it reaches the engine cylinders.

.At a point as near as practicable to the engine the primary mixtureand the secondary air are brought together to form the desired explosive mixture. This is accom plished in the form shown by leading the primary mixture to apertures 62 in the branches of the mixture manifold whence it is discharged into the main body of secondary air fiowin from the exit of the air manifold 61, a mixing chamber 63 being thus formed at the discharge end of the manifolds immediately adjacent to the point of entry to the engine. Tn the operation of this embodiment of my invention it has been observed that upon starting the engine and while it is warming up there will be some accumulation in trap chamber 49 of liquid fuel which has escaped vaporization, and being deflected downwardly by the discharge pipe 48 is collected in the trap chamber and may, if ofsulficient amount to fiow into the stand pipe 51, return to the fuel line. However, after the engine has been in o eration some time it is found that the fuel is substantially completely utilized, the accumulation in the trap chamber being negligible.

In the form illustrated in Figs. 5 and 6, I have shown a four-cylinder engine 100 of conventional type with an exhaust manifold 101. Intakes 102 are arran ed to communicate with the engine cylin ers in any usual or desired manner. Secondary air is supplied at a point adjacent to the cylinders from the air manifold 103 having the air intake 104 controlled by the secondary throttle 105 and the automatic valve 106 corresponding to the .Valve structure-59, 60, v

60' in the fonn previously'described. A carbureter 107 adapted to form a rich primary mixture is provided with a prima throttle 108 connected by rod 109 to secon ary throttle 105. A primary air intake pi e- 110 is adapted to suppl heated air to t e .carbureter, the air'pipe eing heated byexhaust gases in any desired manner as by arranging a portion of the'pipe in the outlet of the exhaust manifold as shown.

Above the throttle valve the intake is enlarged at 111 to form an approximately c'ylindrical separating chamber within which depends a pipe 112 corresponding to the pipe 34 of the form first described, and provided with oblique fins 113 and holes 114. The effect of this device upon the mixture flowing therethrough is to cause a whirling motion whereby the heavier particles are prevented from passing into the pipe 112.

The pipe 112 connects at its upper end with, or is arranged to form, a heating chamber 115 placed within the exhaust manifold 101, and the upper end of theseparato-r chamber constituted by enlargement 111 communicates with'another heating ch amber 116 also located within the exhaust manifold but preferably of greater heating area than the heating chamber 115. These 'heating chambers may be conveniently constituted oftubes bent to form direct and re-' turn branches and of suitable size and length t9 provide the desired heating effect.

The exit end 117 of chamber 115 unites with the exit end 118 of chamber 116 to form the primary mixture manifold 119 which has branches leading to the engine intake openings 102. At these intakes or as near the engine cylinders as practicable secondary airis added by means of the air manifold 120 leading from the secondary air intake 104. The construction of the means for mixing the diluting air with the primary mixture may be of any usual or deiired type, for example, such as is shown in In this embodiment of the invention it will be seen that means is provided for heating both the more completely nebulized material passing through the intake passage 112 and the less fully nebulized portions which have been separated therefrom by centrifugal action in the separatingchamber 111, the relative amounts of heating being determined by the construction of the heating chambers 115 and 116.

In both forms illustrated it will be noted that a primary mixture is. formed which is subjected to a'separating action the effect of which is to remove fuel. portions less completely nebulized which are then subjected to a heat treatment suflicient to bring them to the desired condition for admixture with secondary air.

While I have shown herein electrically heated and exhaust heated means for applying the desired heat treatment to the mixture it-will be understood that. other heating agencies may be employed where convenient and that the heat treatment may be applied to bothportions or to the ortion only containing the larger fuel glo ules. 7 The heating of the primary air may in some cases be omitted or the air and fuel may both be heated, as is common inthis art where fuels of especially low volatility are to be utilized.

Furthermore the separating and heating operations may follow instead of precede the admixture of secondary air, although the latter order is considered preferable.

Various other changes in details ma be made without departing from the spirit of the invention and therefore I wish to cover all modifications and variations within the scope of the appended claims.

I claim: r 1. The method of producing a combustible mixture comprising the formation of a mixture of air and nebulized liquid fuel,

giving to said mixture a rotative movement, withdrawing mixtures of air and fuel from the central and peripheral portions, respectively, of the rotating mass, subjecting the mixtures so withdrawn to heat treatments of different degrees, and recombining the separated portions.

2. The method of producing an explosive mixture for multicylinder internal combustion en ines comprising forming a rich mixture of primary air and nebulized liquid fuel, dividing said mixture into portions each containingv fuel and air, one of which contains the less completely nebulized fuel, subjecting saidlast mentioned portion to treatment for volatilizing the fuel, recombining said portions, conveying the same to points adjacent to the intakes of the res ective cylinders and'then adding the desired proportion of auxiliary air to form an explosive mixture.

3. Means for supplying combustible mixture to an internal combustion engine comprising a carbureter, a separator adapted to receive mixture from said carbureter and separate therefrom a portion containing less completely nebulized fuel, exhaust heated means for heating said portion, electric means for heating the remaining portion means for recombining said portions and means for adding thereto auxiliary air.

4. In fuel treating means the combination of a fuel supply means and a separator associated therewith and comprising a chamber having an outlet communicating therewith through a slot substantially tangential to the chamber, an outlet pi e depending centrally in saidchamber an fins on said pipe adapted to cause whirling movement of said mixture.

5. In fuel treating means, a carburetor, a

separating-chamber for dividing into two.

6. In fuel treating means, a carbureter, a separating chamber adapted to divide into two portions the mixture supplied by said carbureter,Y one of said portions containing 5 the heavier fuel particles in suspension in air, means for treating said latter portion to promote vaporization of said fuel particles therein after withdrawal from said separating chamber, means for separating unvolatilized fuel from said treated portion, and 10 means for recombining said portions.

In testimony whereof I afiix my signature.

FRED E. ASELTINE. 

